The Biostatistical Core will work with all investigators in the Geriatric Oral Science Center. Specifically, the Biostatistical Core will: 1. Collaborate with investigators on the statistical and scientific aspects of study design for each project. The issues to be addressed are definition of endpoints, determination of criteria for selection and enrollment, methods for registration and follow-up, reliability of risk factor assessment, identification of and methods of controlling for possible bias factors, methods for assuring data quality integrity, and adequate sample sizes. 2. Work with investigators on appropriate instruments for data collection. 3. Develop and operate a computer system for data collection, management and statistical analysis. To select and develop appropriate computer software for these functions. 4. Develop and implement a registration and tracking system for study participants. 5. Prepare and distribute monthly accrual reports and quarterly interim reports on data completeness and quality. To monitor study progress to detect problems in implementation or compliance with study protocols. 6. Develop a plan for statistical analysis and graphical presentation of the data in collaboration with project investigators. 7. Develop and/or apply new statistical methodology for the analysis of study results and to develop software to implement these methods. 8. Prepare the annual and final reports on each study and to collaborate with project investigators on the preparation of scientific papers describing study results.